Rotary electric machine having ventilation features



."llg. 25, 1931. p, SUTER 1,820,404

ROTARY ELECTRIC MACHINE HAVING VENTILATION FEATURES Filed Nay 1s, 192e;

yPatented Aug. 25, 1931 siren STATES PATENT orifice :PHILIPP STER, OF BADEN, SWITZERLAND, ASSIGNOR T0 AKTIENGESELLSCHAFT BROWN BQVERI & CIE., OF BADEN, SWITZERLAND, JOINT-STOCK CQMPANY OE SWITZERLAND ROTARY ELECTRIC MACHINE HAVING VENTILATION kIEEA'LLII'RIIS Application filed May 13,- 1926, Serial No.

This invention relates to the construction of rotating electric machines,y such as motors, generators and the like, in which air circulation for cooling is accomplished byy y 5 fans carried on the rotor or rotor shaft.

The general object is the provision of a construction which may be assembled with convenience and which will effect the circulation of air in adequate volume and prop- M10 erly distributed to exercise the desired cooling ventilation.

, One of the 'specific objects is the provision of a construction which will permit the complete assembling of the Vfan or fans on the rotor shaft before the latter is positioned in the frame of the machine.

Other objects will be pointed out or indicated hereinafter or obvious to one skilled in the -art upon an understanding of the invention.

In the drawings forming a part of this specification I show various forms in which the invention may be embodied in electric motors, but it is to be understood that the invention claimed is not to be construed as limited to use in motors or to the particular constructions illustrated.

' In the drawings,

Fig. 1 is a sectional elevation of a motor, taken on an axial line, the parts being illustrated in diagrammatic fashion.

Figs. 2, 3 and 4 are similar diagrammatic sectional elevations of various modified arrangements.

The size, and consequently the power,`of

the fans that can be utilized in rotary eleck tric machines, such as motors having a single l piece stator frame, is limited by the condition that at least one of the fans must be of sufficiently small diameter to pass through the stator tunnel, it being desirable that the assembly on the rotor shaft be complete f before it is assembled with the frame. By the present invention I am able to secure both the desiredr convenience yof assembly and the requisite volume of air circulation and ventilation by the use of two fans, one 1 of which need not be passed through the frame tunnel, kcooperating in such fashion as Vside the frame in a customary manner..

yto effect the proper distribution of cooling 108,762, and in Germany .Tune 18, 19,25.

air to thezmacliine parts. `The nature of" the invention ina-y Vbe most quickly ascertained byreference to the illustrativeein-` 1 which houses the field poles 11 and windings 12,. the arrangement being such that air channels or passages are afforded between these portions and the casing; The inco terior diametery of the field elements accom` modates vthe rotor 14 which is carried on the rotor shaft l5, supported in bearings vout- At oneend of the rotor the vshaft carries theeg fan 16, the same being of the Ycentrifugai type and of such diameter to permit passage through the central tunnel ofthe field assembly. This kfan is positionec near `the end plate orA frame 13 iii front of than@ axial opening 13EL thereof. At the other end of the rotor, the shaft carries ak largeifan 17, also of the centrifugal type, the saine having a position inside the end plate or frame closure 18 in front of the aXialopen-n575 ing 18a. In accordance with the relative capacities of the fans 16 vand 17 the length of the casing-is subdivided by a( partition 19.

yextending between the field pieces and the casing, into two compartments, one on theeo side of the smaller fan 16 and one on the side Vof the'larger'fan 17. These compartments have outlet openings 10a in tlievfraine casing, distributed ,atsuitable points about the same. 'In theoperatioii of the motor-,5&5 the fans16 and 17 draw air intothe casing, through the respective .openings 13`mand18, and deliver it radially so that it is circulated over and aroundl the, portions of the field elements exposedk in their respective 301111-590 partments. As the area vof surface to y,be cooled in the respective compartments bears a relationship to the deliver;7 volume of the r`respective fans, there is obtained the result that the surfaces are cooled to approximate-W95 hut in this case the end frame alongside the larger' fan 17 is closed at the eye portion and has circumferentially-arranged air out-iet openings 18h. Consequently, the Afan draws air through the circumferential openings 10b of the frame casing and expells it through the openings 18h, subjecting the ield elements to its influence. The fan 1G operates as in the arrangement shown in Fig. 1. The openings 10b should be displaced circumferentially with respect to the openings 10YL so that the warm air expelled through the latter will not be drawn back into the casing through the former.

In the arrangement shown in Fig. 3 the fan 16 operates as described above, while the large fan is carried on an element 21, such as a pulley or disk, mounted externally of the motor frame and adjacent the end frame, which has t-he eye opening 18a as in the first instance. The large fan consequently draws air in through the openings 1()b and out through the opening 18a.

In the form shown in Fig. 4, the large fan is arranged as in Fig. 3, but the casing is not partitioned. Consequently, the small fan draws air in through the eye opening 123a and the large fan draws it out through the eye opening 18, subjecting the field elements to its cooling influence as it passes across their surfaces.

What I claim is 1. In a dynamo-electric machine comprising a stator, a rotor, and an enclosing casing, a shaft for said rotor, a fan aixed on said shaft in juxtaposition with one end of said rotor and of diameter not greater than the diameter of said rotor, a second fan alxed to said shaft in juxtaposition with the opposite end of said rotor and of diameter greater than the diameter of said rotor, a partition subdividing the said casing into two compartments commensurate with the relative capacities of the two fans, each said compartment being provided with an inlet and an outlet to permit the flow of a cooling fluid therethrough responsive to actuation of one of the said fans.

2. In a dynamo-electric machine comprising a stator, a rotor adapted for actuation Within said stator, and an enclosing casing divided into two compartments, a. shaft Yfor said rotor, a fan affixed to said shaft in juxtaposition with one end of said rotor and of diameter not greater than the diameter of the said rotor, al second fan affixed to the said shaft in juxtaposition with the opposite end of the said rotor and of diameter greater than the diameter of the said rotor, the said compartments being of unequal capacities and each relatively commensurate with the capacities of the said fans, said casing being provided with an inlet and an outlet for each said compartment so arranged as to permit the fiow of cooling fluid through one of said 

